Martin B. Dines

Lithium intercalation via n-Butyllithium of the layered transition metal dichalcogenides

Abstract n -Butyllithium in hexane solution serves as an excellent reagent to effect the intercalation of lithium into the Group IVb and Vb layered dichalcogenides. Under mild conditions, highly crystalline, uncontaminated stoichiometric products are afforded. In addition, the course of the reaction can be monitored by titration of aliquots of the supernatant.

Intercalation of Metallocenes in the Layered Transition-Metal Dichalcogenides

Novel intercalation complexes of many of the layered transition-metal dichalcogenides incorporating the metallocenes of cobalt and chromium have been prepared. Evidence is presented indicating a configuration in which the five-membered rings of the metallocene guest are situated perpendicular to the slabs of the dichalcogenide host. In the complexes the metallocenes apparently behave as pseudo-alkali metals, transferring an electron to the chalcogenide.

Lamellar zirconium phosphonates containing pendant sulphonic acid groups

Abstract The versatile sulphonic acid group has been introduced into the family of interlamellar anchored materials. Zirconium bis-3-sulphopropylphosphonate is an example of an aliphatic acid. Zirconium bis-2-(sulphophenyl)ethylphosphonate is an example with an aromatic sulphonic acid group. In general, the sulphonic acids are not as crystalline as the carboxylic acid analogs. This is probably due to the relatively large size of the sulphonic acid group compared to the available cross sectional area of the layer face. The aliphatic compounds are more crystalline than the aromatics, as is expected from size considerations. The sulphonic acid group in both crystalline and semi-crystalline examples is accessible to reaction with bases. A few preliminary experiments have demonstrated the utility of these compounds as both strong acid ion exchangers and Bronsted acid catalysts. The layered sulphonic acid—zirconium 3-sulphopropylphosphonate—is thermally stable to well over 200°C. This indicates good potential for applications in Bronsted catalysis. This stability compares favorably with organic resin based sulphonic acids. The sulphonic acid class of interlamellar anchored materials have now been established. Both aliphatic and aromatic examples have been prepared. The utility of the sulphonic acids has been demonstrated with the typical reactions of this functional group. Specifically, the acids have been shown to be strong acid cation exchangers and a Bronsted acid catalyst. In addition, we have begun to develop an insight into the structural ramifications of these compounds. The size constraints of the zirconium phosphate type backbone are evident. Further, the thermal stability of this group of compounds is encouraging relative to its applications potential.

Synthesis and characterization of layered tetravalent metal terphenyl mono- and bis-phosphonates

Abstract The syntheses of p-terphenylphosphonic acid and p,p″-terphenyl-bis-phosphonic acid have been developed, and the resulting products were used to prepare layered Th(IV) and Zr(IV) phosphonates. The monoacidic terphenyl species formed a bilayered structure while the diacid created a pillared geometry. Mixed component phases were also produced. Synthesis, characterization, X-ray and thermal properties of these materials are discussed.